Lockheed unveils its quiet and environmentally green supersonic airliner

"Lockheed Martin have unveiled plans for a “green” and quiet supersonic airliner which is fuelled by hydrogen and doesn’t emit a sonic boom. "

http://walesairnetwork.wordpress.com/2010/07/01/lockheed-unveils-its-quiet-and-environmentally-green-supersonic-airliner/